公开(公告)号：US20170214241A1

公开(公告)日：2017-07-27

申请号：US15175792

申请日：2016-06-07

Applicant: Apple Inc.

Inventor： Xiaofeng Fan ,  Xin Y. Zhang ,  Junjun Li

IPC: H02H9/04 ,  H02H1/00

CPC classification number: H02H9/046 ,  H01L27/0285 ,  H02H1/0007 ,  H02H3/20 ,  H02H9/041 ,  H05K1/0259

Abstract: An apparatus includes a device, a comparison circuit, and a switch. The device includes a first terminal coupled to a first power supply signal, and a second terminal coupled to a ground reference. The comparison circuit is configured to compare a first voltage level on the first power supply signal to a second voltage level of a second power supply signal, and enable the device in response to a determination that the first voltage level is greater than the second voltage level. The switch circuit is configured to couple a power supply terminal of the comparison circuit to the first power supply signal in response to determining that the first voltage level is greater than the second voltage level, and to couple the power supply terminal to the second power supply signal in response to determining that the first voltage level is less than the second voltage level.

公开(公告)号：US10079487B2

公开(公告)日：2018-09-18

申请号：US15175792

申请日：2016-06-07

Applicant: Apple Inc.

Inventor： Xiaofeng Fan ,  Xin Y. Zhang ,  Junjun Li

IPC: H02H3/22 ,  H02H9/04 ,  H02H1/00 ,  H05K1/02 ,  H01L27/02 ,  H02H3/20

CPC classification number: H02H9/046 ,  H01L27/0285 ,  H02H1/0007 ,  H02H3/20 ,  H02H9/041 ,  H05K1/0259

Abstract: An apparatus includes a device, a comparison circuit, and a switch. The device includes a first terminal coupled to a first power supply signal, and a second terminal coupled to a ground reference. The comparison circuit is configured to compare a first voltage level on the first power supply signal to a second voltage level of a second power supply signal, and enable the device in response to a determination that the first voltage level is greater than the second voltage level. The switch circuit is configured to couple a power supply terminal of the comparison circuit to the first power supply signal in response to determining that the first voltage level is greater than the second voltage level, and to couple the power supply terminal to the second power supply signal in response to determining that the first voltage level is less than the second voltage level.